Bucket pressure unloader



IIIIIIIIIIIIIIIIIIIIIIIIII at Oct. 29, 1935. I c. 5 LIP MAN 2,018,917

v BUCKET PRESSURE UNLOADER Filed March 9, 1931 sheets-sheet;

IIIIIIIIIIIIIIIIIIIIII c. .E. LIPMAN 2,018,917

BUCKET PRESSURE UNLOADER Filed March 9, 1931 sands-sheet 2 @2445." WMMMMwM r c. E. LIPMAN BUCKET PRESSURE UNLOADBR Filed March 9, 1931 3 Sheets-Sheet 3 Carlflzl omm Patented Oct. 193s 2,018,917

,TUFNITEDV' STATES PATENT OFFICE Carl E. L. Lipman, Chic 111., assignor to Lipman Patents Corporation, Chicago, 111., a corporation of Delaware Application March 9, 1931, Serial No. 521,278 3 Claims. (01. 230-24) This invention relates to refrigerating systems tion with a sealed motor compressor unit in of thecompressor condenser evaporator type. which at least part of the lubricating oil is posi- In this type of system, particularly in those aptively circulated in combination with the refrigplications thereof wherein the motor compressor erant. i 'unit is hermetically sealed within a casing, it is In the drawings: 5

desirable, and often necessary, for the proper Fig. 1 is a side elevation, with certain parts and succesful operation of the system to reduce broken'away, of a motor compressor unit having the pressure of the high side prior to starting the an unloading device embodying the principles of driving motor, that is, it is necessary to unload this invention incorporated. therein, I the motor at starting if the most efficient motor Fig. 2 is a horizontal transverse section taken for the normal working load is to be employed. on line 2-4 of Fig. 1, h

This feature is particularly desirable'in sealed Fig. 3is a side elevation of the-lower portion units wherein it is necessary to use a motor of as of the unit, certain parts being broken away, lowcapacity and small size aspossible; In reillustrating the unloading mechanism in closed 3 ducing the pressure upon the high side of the position,

compressor it is. also necessary, of course, to pre- .Fig. 4 is a view similar to Fig. 3 illustrating the vent the relatively warm refrigerant from passunloading mechanism in operative position, ing back through the suction lirie into the low A Fig. 51s a" fragmentary section on line 6-5 of side and into the evaporatorunit. Otherwise, the Fig. 3, I reverse flow of refrigerant will transfer heat to Fig. 6 is a perspective detail of the principal the expansion or evaporating element and result parts of the unloading mechanism, and in a considerableloss in efliciency. Fig. '7 is a diagrammatic illustration of a com- It is, therefore, aniobject of this invention to plete refrigeratingsystem embodying a motor provide an unloading mechanism for use in a compressor unit having incorporated therein the i refrigerating system which will materially reduce unloading mechanism embodying the principles the pressure in the high side of the system'prior of this invention. to'sta'rtingof the driving motor. With particular reference to'Fig. 1, it will be It is also an object of this invention to pro seen that the motor'compressor unit is carried by vide such an unloading device which is actuated a base I and is hermetically sealed by a shell or 1 through some medium such as the lubricating or dome 2. The unit comprises .generally a comseal oil, that is put into operation by operation of pressor I mounted upon a pedestal 4 arising from the motor compressor and which ceases to func-- the center of the base i and driven by a motor 5 tion during idle periods of the motor compressor. carried by a spider 6. The particular compressor It is also an object of this invention to provide illustrated is arranged to discharge the refrigeri an unloading device that is actuated by the cirant under pressure into the interiorof the dome culating lubricating oil for the motor compressor and the lubricating oil through the central bore I in units where the oil is posltivelycifculated; of the central shaft 8, from which it is drawn It is still a further object of this invention to outwardly against the baflle or distributor 9, after provide an unloading device of this character which it falls down over the stator of the motor. 1 which may be incorporated within the sealed con- Arranged beneath the stator of the motor is tainer of an hermetically sealed motor coman arcuate tray or cup-like member I! disposed pressor unit'. A to collect a portion of the oil dripping from the In accordance with this invention, a medium stator. The seal oil customarily circulated with set in operation by the compressor such as the the refrigerant or .which may be unavoidably i circulating lubricating oil is utilized to actuate mixed therewith may be utilized instead of the a valve which controls a passage between the *lubricating oil by merely piping it into the tray. high and low sides of the compressor for sub-' The tray is secured to one end of a yoke I: which stantialLv equalizing the pressures therebetween straddles the compressor. and is pivoted interat predetermined periods. mediate. its length upon a pair of trunnion pins 1 Other and further oblects and their resultant l4 threaded in and projecting through a bracket advantages will'be apparent after this invention II the latter being rigidly secured to the supbecomes better understood from an examination porting spider .6. The opposite end of yoke 13 of the specification and claims in connection with is provided with a counter-weight which is of the accompanying drawings in which one appli proper weight as to overbalance'the bucket I2 5 cation of this invention is illustrated in connecwhen empty, but to be raised by the bucket I -ing II secured to bracket. The operative conmotion between bucket i2 and valve I9 is made through the medium of an inverted .cup 12 which is provided with a iarge'and adjacent sniali aperture form a keyhole joint which loosely engages ehead 23 and cup 12'.

The valve casing is connected to the suction side of the compressor by a by-passtube 2i tapped into the intake duct 16. The valve memher, I! being rectangular and slidable within a circular housing, the valve establishes communi-- cation when open between the suction side and the interior of the dome 2. Thus, when the valve is open, pressures between the high and low sides are substantially equalized.

The operation of the unloading mechanism iust described is believed to be apparent, but will be summarized briefly. During running periods of the motor compressorunit, oil will be thrown out over the top of the motorand will drain downwardly thereover, some of it falling into bucket l2. When the bucket becomes substantially filled with oil, the weight thereof will overbalance weight II and lower valve ll upon its seat. This will interrupt the communication between the low and high sides of the compressor and allow the pressure on thehigh side to build up. when the motor compressor unit stops the supply of oil into bucket II will, of course, cease and the oil therein will drain out slowly through aperture II. This will permit'the weight I! to swing the. yoke about its pivot and raise bucket 22, thereby raising valve member is from its seat. Opening of the valve will establish communication between the high and low sides through tube 24 which will unload the compressor preparatory to the succeeding running periodsoi' the motor compressor.

In Fig. 'I there 'is illustrated a complete refrigerating system in which the motor compressor unit supplies refrigerant through connection it and a discharge line 21 to a refrigerant circu-r latory system including a condenser 28 forliquefying the refrigerant. a float chamber 2! for controlling the flow of refrigerant through the liquid line II to a cooling element such as an evaporator". From the evaporator I! the va porised refrigerant is withdrawn back to the compressor through a suction'line SI which includes a check valve 34 to prevent reverse flow of refrigerant from the compressor back through the suction'line into the evaporator. In the illustrated unit a portion, at least, of the lubricating oil is circulated through an oil cooler 3! through connecting pipes Il.

I p 8,018,917 when filled with oil. Bucket II is provided with l'romtheforcgoingdisclomreitwillbeapparentthattherehasbeenprovidedanunloadim thatisactuatedinresponsetothe operating condition of the motor compressor unit .through the lubricating oil. The unit is convenientiy adapted to be' incorporated within the sealing dome of the sealed motor compressor unit, althoughitismanifestthatitmaybeincorporated externally thereof with some suitable housins if so desired. 1

Jtisobviousthatminorchsngesmaybemade in the details of the construction without departing from the spirit and scope of this invention as defined in the claims.

I claim: a

l. A hermetically sealed motor compressor unit having means for circulating lubricating oil therethrough, a hy-pass between the high and low pressure sides of the compressor. a valve in said by-pass. a pivoted'oil cup disposed beneath a portion of the motor compressor unit and arranged to collect a portion of the oildripping therefrom, said cup having a restricted drain opening, a counter-balance for said cup and connectionsbetween said cup and-said valve for actuating the latter to substantially equalise'the pressures in the high and low pressure sides'ot said compressor upon stopping of the latter.

2. A motor compressor unit adapted to be operatedintermittently comprising a compressor. means for circulating lubricant, a' by-pass connection between the high and low sides of the compressor. a valve for controlling said lay-pass.

a movably mounted receptacle podtioned to collect circulated lubricant and connected to said valve to close the same when weighted by collected lubricant. said receptacle having a restricted delivery opening permitting a delayed drainage of the collected lubricant therefrom. andmeansforopeningsaidvalveuponthr drainage of lubricant from said receptacle.

3. Amotorcompressoradaptedtobeoperated intermittently comprising a refrigerant eompm sor,amotorforoperatingthesame,meansfo1 circulating lubricant. a e throimh which communication between the high and low side: of said compressor may-be established, a valvl for closing said passage.'a'fulcrumed lever 101 operating said valve. a receptacle connected t: said lever and-positioned to collect circulate: lubricant, said receptacle being adapted to elect said valve when weighted hycollected lubricam and having-a restricteddelivery'open'ing permittingadelayed'drainageofthecollectedlubri' cantthereimandgravity actuatedmeansfm operatingsaidlevertoopensaidvalveupoi drains-kc of lubricant from said receptacle.

CARI-Elam. 

